I. Field of the Invention
The present invention relates generally to wireless communication devices (WCDs), and more particularly, to such a wireless communication device (WCD) capable of interacting with multiple beams in a satellite or a terrestrial based communication system.
II. Related Art
A known satellite communication system uses satellite beams from multiple communication satellites to provide communication signal connectivity between a large number of geographically distributed user satellite terminals and multiple satellite ground stations, referred to as gateways. At any given time, one or more satellite beams from one or more of the satellites illuminate each user terminal. A typical user terminal, also referred to herein as a wireless communication device (WCD), includes a finite number of satellite beam tracker resources, referred to as receiver “fingers.” The receiver fingers track communication signals within the satellite beams illuminating the WCD. Typically, a finger tracks various characteristics of a communication signal, such as an energy level, a frequency offset, a spreading code offset when the signal is a spread spectrum signal, and so on, to enable the WCD to demodulate and recover information from the communication signal.
Relative motion between the satellites and a WCD creates a dynamic environment, wherein different satellite beams sweep past, and thus illuminate, the WCD over time. To accommodate this dynamic environment, it is desirable for the WCD to be able to allocate and reallocate the finite number of fingers between the different beams dynamically, whereby the WCD can maintain connectivity with the communication system over time. In other words, it is desirable for the WCD to be able to assign and reassign various ones of the fingers to the different satellite beams over time, so that at any given time, the fingers track the one or more satellite beams illuminating the WCD.
The ability of a finger to track a satellite beam successfully, that is, the ability of the finger to track the signals within the satellite beam, depends on an energy of the beam as received at the WCD. For example, the greater the beam energy, the greater is the ability of the finger to track the beam successfully. Therefore, it is desirable that the WCD allocate fingers to satellite beams dynamically, and in such a manner as to maximize the beam energies delivered to the fingers.